On Fri, Aug 12, 2016, Robert Molt wrote:
>
> I am confused on an aspect of parameter values in the GAFF/Amber force
> fields. Using defaults of ff14SB for a molecule I put through
> Antechamber, the frcmod file has the value
>
> CA-CA-CT-OS 1 0.000 0.000 2.000 same as X
> -c2-c3-X
>
> for the above dihedral. My understanding is that the order of parameters
> goes dividing factor, k force constant, n periodicity, phi phase angle.
You can find this in $AMBERHOME/dat/leap/parm/gaff.dat, as X-c2-c3-X, along
with a literature reference. Aliphatic torsions are often either very close
to zero, or exactly zero, since there is little intrinsic barrier to rotation.
...hope this helps...dac
_______________________________________________
AMBER mailing list
AMBER.ambermd.org
http://lists.ambermd.org/mailman/listinfo/amber
Received on Sat Aug 13 2016 - 13:00:02 PDT
